Yeah, I had left the OE cam seal after several TB changes because it was not leaking. Well, at the last TB change, I had to replace the Crankshaft seal due to a leak. So, I thought well, I'll go ahead and replace the Cam Seal...........bad idea! It now leaks! The Crankshaft seal is fine!
Some things need to be left alone if they are not giving a problem.........the Cam Seal is one of those things!...........in my opinion! I believe the other posters concur!